plonetheme.onegov: Support custom styles.
Drop plone 4.2 compatibility
Fix typo in HISTORY.txt
Re-enable Plone 4.2 tests, but only test plonetheme.onegov integration in 4.3.
Merge pull request #14 from 4teamwork/mle-onegov-theme

plonetheme.onegov: publish custom styles